Overload switch or cut-out.



P. G. VAN WIJK.

OVERLOAD SWITCH 0R CUT-OUT.

APPLICATION FILED MAY 23 |916.

Patented 001. 1, 1918.

cfmk

@Montag-5.

- PIETER GERBIT VAN WIJK, 0F GELDERMALSEN, NETHERLANDS.

OVERLOAD SWITCH OB CUT-OUT.

Specication of Letters Patent.

Application led May 23, 1916. Serial No. 99,357.

To all whom t ma concern.'

Be it known t at I, PIETER GERRIT VAN WIJK, subject of the Queen of the Netherlands, residing at Geldermalsen, Kingdom of the Netherlands, have invented certain new and useful Improvements in or Relat- 'ing to Overload Switches or Cut-Outs, of

which the following is a specification.

This invention relates to automatic overload switches having a delayed or retarded action. The object of the invention is to provide a switch of this kind of sim le construction and suflicient reliability o action, and in which the duration of the delay can be regulated in a simple manner.

According to this invention, the part which normally holds the switch locked, is held in contact with the circumference of a disk rotatable about a xed spindle, by springs or by a weight. The said disk is provi ed in lts circumference with a recess into which thelocking bar can be forced by spring pressure or by the action of a weight, when t e disk is turned to such an extent that the recess is brought opposite the locking bar. The turning of the disk is effected by the attraction of an iron core by a coil. The rotation of the disk is retarded owing to its spindle driving, by means of a speedmultiplvng gear, an auxiliary spindle which rives one or more rollers or sliding parts which, during their rotation about the said spindle, are pressed, in opposition to the action of springs, by centrifugal force with adjustable tension against the inner circumference yof a fixed hollow cylinder, the axis of which coincides with the axis of rotation of the said rollers.

A construction according to this invention is illustrated by way of example in the accompanying drawing in whichi Figure 1 is a side elevation of the release,

Fig. 2 a front elevation,

Fig. 3 a side elevation of that part of the apparatus which brings about the retardation or delay, and

Fig. 4 is a front elevation of the parts shown in Fig. 3.

The knife contacts 1 of the switch are locked by a locking pawl 2 which can be disenga ed by means of the unlocking bar 3. The knife contacts are then lifted in the known manner by the action of the weight 4, out of the spring contacts 5, and the lever 6 to which the weight is secured, strikes against a fixed stop. The unlocking bar 3 is raised by a spring 8 and on its upper end is a roller 9, for the purpose of reducing the friction, whichengages with the circumference of a disk 10 rotatable about a pin 11 mounted in the frame 12 of the apparatus.

When the apparatus becomes operative, that is to say when the strength of current rises so high that the soft iron core 13s completely attracted by the coil 14, the disk in question will be rotated until a recess 15 provided on the circumference of the disk is brought opposite the roller 9. The unlocking bar 3 will then be forced upward by the pressure exercised by the spring 8. Its upper end will enter the recess 15 and lift out the locking pawl 2, so that the switch will be disengaged, and the circuit broken.

The spindle 11 which is turned owing to the movement of the core 13, drives an auxiliary spindle 20 at ahigh speed by means of intermediate toothed wheels 16, 17 and 18, 19` or in some other way. lThis auxiliary spindle, together with the spindle 21 which supports the toothed wheels 17, 18, is mounted in brackets 22 secured to the wall plate of the apparatus. To the said wall plate is secured a hollow cylinder 23, the axis ofv which coincides with the axis of rotation of' the spindle 20. The spindle 20 has, in theinterior of the cylinder 23, a part 24 of a larger cross-section; the part 24 is provided with one or more holes 25 extending normally to the spindle 20. In the said holes are guided rods 26, one end of which is bifurcated and carries a roller 27, while the other is screw-threaded and carries a nut 29; and a spring 28 is arranged between thepart 24 and the nut, which spring is com-- pressed when the rollers 27 move away from the spindle 20 about which they rotate.

By adjusting the nuts 29 on the rods 26,

the spring tension can be regulated in a convement manner, whereby the centrifugalL Patented Oct. 1, 1918..,

comparatively slow rotation is transmitted by the toothed wheels 16, 17, 18 and 19 to the spindle Q0 which.) oving to the speedmultiplying gear, is driven at a high speed. The centrifugal force produced by the rotation, presses the rollers 2T, in opposition to the action ot the springs against the inner circumference of the cylinder suitably secured to bearings 2Q, and owing to the friction thus produced, retards the movement7 Kso that the speed of rotation of the disk l0 is reduced. rIhe tension of the springs Q8 can-be regulated as desired by means of the nut-s Q9, and in that way also the resistance offered by the retardation deice. and consequently also the time elapsing bei'ore the disk 10 reaches the end position in which the switch is opened.

Then the disk 10 has turned so tar that the recess 15 is opposite the unlocking bar 3, the latter will be forced upward into the recess by the spring S. The unlocking barl after having traveled a short distance, will then strike with a bolt or stop against the locking pawl which will be lifted out, whereupon the switch will be brought into the open position by the action ot' the weight 4. i

:in advantage of the switch according to the invention consists in the simplicity of regulation, so that the admissible overload duration can be set exactly Jfor every individual case.

lVhat I claim is:

1. An automatic overload switch or cutout comprising a switch-arm adapted to be released by means of a cam rotated by means of an electromagnetic device operated by the excess of current, a spindle driven at a high speed by said electromagnetic device, rollers mounted on said spindle and adapted tobe t'oi'ced outward by vcentrifugal force, a hollow cylinder coaxial with and surrounding said spindle and adapted to be engaged by said rollers, and adjustable springs adapted to restrain the outward movement oit the rollers.

2. An automatic overload switch or cutout comprising a switch-arm, means always tendine' to move said arm into the. open position, a locking bar adapted to hold the arm in the closed position, a cam disk engaged by said locking bar and having a notch adapted to admitthe locking bar and thereby to release the switch arm, means for rotating said cam disk automatically when the current roaches a certain maximmmand j adjustable means for delaying said rotation.

3. An automatic overload switch orA cutout comprising a switch-arm, means always tending to move said arm into the open position, a locking bar adapted to hold the arm in the closed position, a. camy disk engaged by said locking bar and having a notch adapted to admit the locking bar and thereby to release the switch-arm, electromagnetic means operated `by any excess of current for rotating said cam` disk, and an adjustable friction `brake adapted to delay the rotation ol said disk, and means for ad, just-ing the duration of ysaid delay.

In testimony whereof I have'hereunto set my hand in presence of two subscribing wit HQSSGS.

PIETER GERRITvAN WIJK. Witnesses:

D. KLEYN, Ron Booeoom).

Copies of this patent may be obtained for ve cents each, by addressing the' Commissioner of Patents,

, waxhingtoml). C. i 

